Method and apparatus for forming cellular structures



M. DALO Aug. 28, 1956 METHOD AND APPARATUS FOR FORMING CELLULAR STRUCTURES 4 Sheets-Sheet 1 Filed March 25, 1953 L llllllll MARIO DAL-O M. DALO Aug. 28, 1956 METHQD AND APPARATUS FOR FORMING CELLULAR STRUQTURES 4 Sheets-Sheet 2 Filed March 23, 1953 IHVEHToR MAR/0 DALO 6Y 28, 1956 M. DALO 2,760,548

METHOD AND APPARATUS F OR FORMING CELLULAR STRUCTURES Filed March 23, 1953 4 Sheets-Sheet 3 INVENTOK.

MAR/o 8Y Aug. 28, 1956 M. DALO 2,

METHODIAND APPARATUS FOR FORMING CELLULAR STRUCTURES Filed March 23, 1953 4 Sheets-Sheet 4 Inventor m l/ 0 Dab NIETHOD AND APPARATUS FOR F This invention relates to the manufacture of constructional elements having a great strength with a very light weight. Such elements are increasingly utilised in the most varied technical fields. They are most often constituted by volumes of cellular networks of thin wood, cardboard or like material, and are formed with laminae of this material, disposed so as to present a restricted number of longitudinal points of contact while constituting sectionaliy a very extensive supporting surface.

The most advantageous cellular network of this kind is that constituted by regularly corrugated laminae disposed side by side with a longitudinal displacement equal to half a corrugation, that is to say the corrugations of which are successively opposed to each other. Such a network then presents, for a minimum weight, a maximum strength against crushing.

Up to now, the manufacture of such networks necessitated two successive separate operations, namely, first the impression of the corrugations on the laminae, then their approach and their uniting. The first operation is easily carried out by means of fluted rollers. The second operation, on the contrary, necessitates a considerable expenditure of labour and time in order to be carried out in a satisfactory manner. Moreover, it has hitherto been impossible to perform these two operations continuously so as to obtain networks the dimensions of which are practically unlimited.

The present invention permits to obviate these drawbacks. It enables to carry out in a single operation, continuously, the manufacture of networks of the type referred to, of practically unlimited dimensions.

The invention has for its object a machine comprising means for continuously feeding laminae of material such as wood, cardboard or the like, up to a working zone, means for coating the laminae with a suitable adhesive before their arrival to the said working zone, means for the preliminary shaping of the laminae so as to prepare the shape which they are ultimately to assume, means for impressing the latter shape to the said laminae, means for subjecting the said shaped laminae to such a pressure and heat that they preserve their shape permanently while remaining attached to each other, and means for discharging the network so constructed from the working zone.

The essential part of the machine is naturally that one designated under the name of working zone. In this zone, the laminae, which are parallel on arriving, are first deformed, then pressed hot in such a way that the whole of their surface is subjected to the pressure. The operation, which comprises three stages transforms the said laminae into the desired network.

. This working zone contains the means enumerated above and which consist of a series of pairs of steel tubes heated internally and of thin caps surrounding these steel tubes, the assembly of each element of these pairs being capable of independent motion.

The thin caps are intended to penetrate between the parallel laminae, for the purpose of subsequently sepa-.

rating them in order to impart to them the shape which they have, and which they preserve, in the finished network. If one considers the parallel horizontal laminae, the caps are therefore possessed of a vertical movement and penetrate between the thin sheets; this is the first stage of the operation.

Subsequently, the rigid steel tubes in their turn perform a similar movement and penetrate into each corresponding cap. The result of this movement is the separation of the caps, and therefore of the laminae, without any rubbing of the steel on the laminae. These latter then assume their shape. This is the second stage of the operation.

Finally, in order that the network be formed solidly, it is necessary that the whole be submitted to a strong lateral pressure so that the laminae impregnated with adhesive are individually subjected to pressure, while heat is applied to the whole assembly.

In practice, the steel tubes are heated by means of internal electric resistances.

'The lateral pressure is obtained by means of jacks compressing the block of assembled laminae-caps-- tubes of heated steel. In practice, this pressure is con- -siderable, to such an extent that the thickness of the laminae at the points of adhesion is reduced from 5 to 30% and preferably from 10 to 25%. The obtaining of this pressure presents a particular problem owing to the fact that the caps and the tubes are guided, according to the invention, by means'of a horizontal grating the pattern of which is approximately similar to that it is desired that the network should have. The crushing of each lamina is equivalent to a displacement of the extreme elements which is equal to as many times the value of this crushing as there are laminae between the centre, which is fixed, and the end of the machine.

According to the invention, this problem has been solved by constituting this said grating with transverse elements, themselves corrugated concertina-fashion, these transverse elements being freely traversed by longitudinal elements, so that, under the action of the pressure applied to the grating, the transverse elements are compressed Concertina-fashion while their active length decreases, while the longitudinal elements follow this compressing while remaining parallel to themselves.

The invention will be better understood with reference to the following description which refers to the accompanying diagrammatic drawings which represent, in the way of example, a preferred embodiment of the invention, and in which:

Fig. 1 is a front view of the machine, the accessory parts being removed and the two halves, on either side of the middle vertical line, showing the position of the essential members in the first two stages of the operation.

Fig. 2 is a lateral view of the machine.

Fig. 3 represents a separating tube.

Fig. 4 represents the cap adapted to co-operate with the tube.

Fig. 5 represents a pre-guiding comb.

Fig. 6 is a sectional view showing the relative disposition of the diflferent members and of the laminae in the crushing position, along VIVI of Fig. 1.

Fig. 7 is a perspective View of the guiding grating of the caps and of the tubes.

Fig. 8 is a section along VIIIVIII of Fig. 7.

Fig. 9 is a view of detail of analternative arrangement.

Fig. 10 is a top view showing different members of the machine in a position in which these members are Withdrawn from between the laminae. v

Fig. 11 is a sectional view corresponding to Fig. 10, the's ection being taken along lines 1111 of Fig. 10 and viewed in the direction of the arrows.

Fig. 12 is a sectional view taken along the line 12-12 of Fig. 13 viewed in the direction of the arrows, in which the members are shown in an operative position.

Fig. 13 is a sectional view taken along the line 13-13 of Fig. 12 viewed in the direction of the arrows.

Fig. 14 is a sectional view taken along the line 14-14 of Fig. 15 viewed in the direction of arrows, in which the members are shown in a position following the position shown in Fig. 12.

Fig. 15 is a sectional view taken along the line 15-15 of Fig. 14 viewed in the direction of the arrows.

In the drawings, 1 is the frame of the machine, mounted on a bed 2. Laminae of wood, cardboard or like material are unwound from reels 4, pass through a device 5 for coating them with adhesive, through a comb for imparting to them a preliminary shape, shown at 6 in Fig. 5, and arrive at the working zone 7. In this zone, a series of caps 8 carried by a frame 12 are adapted to receive a vertical movement under the action of jacks 13, while above, a same number of steel tubes 11, carried by a frame 9, may be pushed into the caps 8 under the action of jacks 10.

The caps and the tubes are guided between the laminae 3 by at least two horizontal gratings 14, disposed on either side of the laminae. On each side of these gratings 14, jacks 15 are adapted to exert the required pressure on the assembly. Finally, the completed network 16 is discharged by transporting belts 17.

The preliminarily shaping comb 6, clearly seen in Fig. 5, has for its purpose the separation of the laminae 3, which are parallel when they arrive, and to impart to them a shape which will more easily allow the insertion of the caps 8 between them. This comb is constituted by teeth 18 disposed on a plate 19 rocking about an axis 20 with respect to the frame 1. These teeth are terminated by swelling 21 disposed in a manner somewhat similar to the distributon of the cells of the network it is desired to obtain.

The tubes 11 have preferably the shape represented in Fig. 3, that is to say they comprise an engaging end 22 which is pointed and a resilient tail 23, while the caps 8 have the shape represented in Fig. 4, comprising two wings 24 united at 25 and terminated at. the base by a device 26 for securing them. In order to allow for the displacement of the tubes and of the caps relatively to each other, it is necessary that this device 26 for securing them be at least as long as the tubes 11.

Finally, there is represented in Figs. 7 and 8 an embodiment of a grating 14, adapted, according to the invention, to be deformed under the action of the jacks 15. This grating is constituted with transverse elements 27 and longitudinal elements 28. The first ones are blades of corrugated steel, are resilient, and capable of changing their shape, concertina-fashion, under the effect of the pressure of the jacks 15. These blades are perforated at 29 in order to allow the passage of the longitudinal elements 28. These latter, as is best seen at 28a, comprise a central portion 30 corresponding to the perforations 29, and two extreme portions 31, guided longitudinally by the blades 32 sliding in the space limited by the blades 27 on the one hand and shoulders 33 on the other hand. The central portions 31) are maintained in the opening 29 by riders 35 acting as guides for the wings 24 at the beginning of the movement of the caps 8.

The working of the machine is as follows:

The laminae 3 are unwound from the reel 4 and transported through the coating device 5 where they are coated with an adhesive. From there on, they are moved through the comb 6 and preliminary shaped by the same and pass finally into the working zone of the machine between the two gratings 14. During the time of the feeding, the shaping means, that is, the caps 8 with the wings 24 and the tubes 11, are in inoperative position, that is in the position as shown in the right side of Fig. l and as illustrated in the Figs. 10 and 11. The feeding is then stopped and the shaping means are moved from the inoperative position in which they are withdrawn from between the laminae into the operative position between the laminae as shown on the left side of Fig. 1 and as illustrated in the Figs. 12 and 13. The caps 8 supported on the frame 12 move first upwardly by means of the jacks 13 between the laminae or adhesive coated strips 3 and during this movement the wings 24 of the caps 8 are close together or in collapsed position, as clearly shown in Figs. 8, 12 and 13 of the drawings. The outer edges of these wings 24 are guided during this upward movement by the riders 35 attached to the central portions 30 of the longitudinal element 28 of the gratings 14. After the caps 8 have thus moved in between the coated strips 3, the tubes 11 attached to frame 9 are moved upwardly by the iacks 10 and spread the wings 24 from the collapsed position into an expanded position as shown on the left side of Fig. 1 and as also indicated in Figs. 6, 14 and 15. Thereby, the coated strips 3 are deformed and obtain approximately their final shape as shown in Figs. 6 and 14. The tubes 11 are therefore expanding means for the collapsible tubular shaping means constituted by the wings 24 of the caps 3. Finally the whole structure is transversely compressed by the jacks 15 while the tubes 11 are heated and insure the drying of the adhesive and the joining of adjacent laminae at the points 35 between the tubes 11.

As mentioned before, the coated strips are compressed at their joining points approximately 10 25% and uniform compression is made possible by the concertinalike compression of the transverse elements 28 of the gratings 14 and the resilience of the caps 8 and the tails 23 of the tubes 11, whereby the elements 28 of the gratings form spaces between opposite wings 24 on adjacent caps. As can be seen from Figs. 6 and 14 the wings 24 insure the contact of the laminae over the whole surface. The jacks are then withdrawn to their original position whereby the transverse elements 27 of the gratings expand to their original form and the element 23 shifts the upper ends of the caps 8 and tubes 11 transversely. Then the jacks 10 are lowered and thereby the tubes 11 are withdrawn from between the wings 24 of the caps 8 so that the wings will return from their expanded position to their collapsed position and become detached from the coated strips 3. Finally, these collapsed caps are withdrawn from between the coated strips 3 by lowering the jacks 13. After all members of the machine have been returned to their starting positions, the cycle is repeated.

According to an alternative arrangement, shown in Fig. 9, the caps 36 carry at their lower portion slides 37 engaged in guides 38, which permit their displacement parallel to themselves. In these caps are introduced the tubes 35?, themselves fixed to vertical blades 40 capable of bending resiliently while remaining parallel to the guides 35, the base of these blades being fixed on a frame 41 acted upon by the jacks.

In this manner, not only is the movement of the caps and tubes ensured to be vertical, but, under the action of the horizontal jacks, they may receive the small displacement parallel to themselves, which comes advantageously to complete the mounting of the grating to permit the compression of the laminae without disturbing the vertical direction of the latter.

What I claim is:

1. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; shaping means mounted on said support means movably between an operative position projecting between the thus adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; moving means for movave- 548 ing said shaping means between operative'and inoperative position; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping means in operative position inserted therebetween for joining together said strips shaped by said shaping means at points spaced by said shaping means so as to form said strips into a cellular structure.

2. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; means for pro-shaping the thus adhesive-coated strips; shaping means mounted on said support means movably between an operative position projecting between the thus preshaped adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; moving means for moving said shaping means between operative and inoperative position; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping means in operative position inserted therebetween for joining together said strips shaped by said shaping means at points spaced by said shaping means so as to form said strips into a cellular structure.

3. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; collapsible tubular shaping means mounted on said support means movably between an operative position projecting between the thus adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; elongated expanding means mounted on said support means movable for insertion into said collapsible tubular shaping means while the latter are in operative position for expanding the same and movable for withdrawal therefrom; moving means for moving said shaping means between operative and inoperative position and for moving said elongated expanding means into and out of said shaping means; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping means in operative position inserted therebetween for joining together said strips shaped by said shaping means at points spaced by said shaping means so as to form said strips into a cellular structure.

4. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; shaping means mounted on said support means movably between an operative position projecting between the thus adhesivecoated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; moving means for moving said shaping means between operative and inoperative position; guide means mounted on said support means for guiding said shaping means in movement thereof into operative position between said adhesive-coated strips; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping means in operative position inserted therebetween for joining together said strips shaped by said shaping means at points spaced by said shaping means so as to form said strips into a cellular structure.

5. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable "material along a path on said support means; means 'for coating with an adhesive material said plurality of strips during movement thereof along said path; a plurality of collapsible tubular members mounted on said support means movably between an operative position projecting between the thus adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; a plurality of elongated expanding members mounted on said'support means movable for insertion into said collapsible tubular shaping members while the latter are in operative position for expanding the same and movable for withdrawal therefrom; moving means for moving said shaping members between operative and inoperative position and for moving said elonga-tedexpanding members into and out of said shaping members; grating means mounted on said support means for guiding said shaping members in movement thereof into operative position between said adhesive-coated strips; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping members inoperative posit-ion inserted therebetween for joining together said strips shaped by said shaping members at points spaced by said shaping members so as to form said strips into a cellular structure.

6. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; a plurality of collapsible tubular members mounted on said support means movably between an operative position projecting between the thus adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesive-coated strips; a plurality of elongated expanding members mounted on said support means movable for insertion into said collapsible tubular shaping members While the latter are in operative position for expanding the same and movable for withdrawal therefrom; moving means for moving said shaping members between operative and inoperative position and for moving said elongated expanding members into and out of said shaping members; compressible grating means mounted on said sup" port means for guiding said shaping members in movement thereof into operative position between said adhesive-coated strips; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping members in operative position inserted therebetween while simultaneously compressing said compressible grating means for joining together said strips shaped by said shaping members at points spaced by said shaping members so as to form said strips into a cellular structure.

7. Apparatus for forming a cellular structure comprising, in combination, support means; transporting means for moving a plurality of spaced parallel strips of bendable material along a path on said support means; means for coating with an adhesive material said plurality of strips during movement thereof along said path; collapsible tubular shaping means mounted on said support means movably between an operative position projecting between the thus adhesive-coated strips when the same have moved along said path and an inoperative position withdrawn from between said adhesivecoated strips; elongated heated expanding means mounted on said support means movable for insertion into said collapsible tubular shaping means while the latter are in operative position for expanding the same and movable for withdrawal therefrom; moving means for moving said shaping means between operative and inoperative position and for moving said elongated expanding means into and out of said shaping means; and compressing means for compressing said spaced parallel adhesive-coated strips together with said shaping means in operative position inserted therebetween for joining together said strips shaped by said shaping means at points spaced by said shaping means so as to form said strips into a cellular structure.

8. A method of making a cellular structure comprising the steps of moving a plurality of spaced substantially parallel strips of bendable material in the direction of their length; applying an adhesive coating on said plurality of strips during movement thereof; inserting collapsible shaping members between the thus adhesive-coated strips; expanding said collapsible shaping members while arranged between the strips; compressing the adhesive-coated strips together with the thus expanded shaping members arranged between said strips so as to join together the strips thus shaped by the shaping members at points spaced by the shaping members, thereby forming the strips into a cellular structure; and withdrawing the shaping members from between the thus shaped and joined strips.

9. A method of making a cellular structure comprising the steps of moving a plurality of spaced substantially parallel strips of bendable material in the direction of their length; applying an adhesive coating on said plurality of strips during movement thereof; inserting collapsible shaping members between the thus adhesive-coated strips; inserting heated expanding members into said collapsible shaping members for expandthe same while the latter are arranged between the strips; compressing the adhesive-coated strips together with the thus expanded shaping members arranged between said strips so as to join together the strips thus shaped by the shaping members at points spaced by the shaping members, thereby forming the strips into a cellular structure; withdrawing the expanding members from the shaping members so as to collapse the latter; and withdrawing the thus collapsed shaping members from between the thus shaped and joined strips.

References Cited in the file of this patent UNITED STATES PATENTS 1,115,138 Wilkes Oct. 27, 1914 1,475,305 McClenny Nov. 27, 1923 2,365,754 Gramelspacher Dec. 26, 1944 2,445,290 Gouda July 13, 1948 2,454,719 Scogland Nov. 23, 1948 

1. APPARATUS FOR FORMING A CELLULAR STRUCTURE COMPRISING, IN COMBINATION, SUPPORT MEANS; TRANSPORTING MEANS FOR MOVING A PLURALITY OF SPACED PARALLLEL STRIPS OF BENDABLE MATERIAL ALONG A PATH ON SAID SUPPORT MEANS; MEANS FOR COATING WITH AN ADHESIVE MATERIAL SAID PLURALITY OF STRIPS DURING MOVEMENT THEREOF ALONG SAID PATH: SHAPING MEANS MOUNTED ON SAID SUPPORT MEANS MOVABLY BETWEEN AN OPERATIVE POSITION PROJECTING BETWEEN THE THUS ADHESIVE-COATED STRIPS WHEN THE SAME HAVE MOVED ALONG SAID PATH AND AN INOPERATIVE POSITION WITHDRAWN FROM BETWEEN SAID ADHESIVE-COATED STRIPS; MOVING MEANS FOR MOVING SAID SHAPING MEANS BETWEEN OPERATIVE AND INOPERATIVE POSITION; AND COMPRESSING MEANS FOR COMPRESSING SAID SPACED PARALLEL ADHESIVE-COATED STRIPS TOGETHER WITH SAID SHAPING MEANS IN OPERATIVE POSITION INSERTED THEREBETWEEN FOR JOINING TOGETHER SAID STRIPS SHAPED BY SAID SHAPING MEANS AT POINTS SPACED BY SAID SHAPING MEANS SO AS TO FORM SAID STRIPS INTO A CELLUILAR STRUCTURE.
 8. A METHOD OF MAKING A CELLULAR STRUCTURE COMPRISING THE STEPS OF MOVING A PLURALITY OF SPACED SUBSTANTIALLY PARALLEL STRIPS OF BENDABLE MATERIAL IN THE DIRECTION OF THEIR LENGTH; APPLYING AN ADHESIVE COATING ON SAID PLURALITY OF STRIPS DURING MOVEMENT THEREOF; INSERTING COLLAPSIBLE SHAPING MEMBERS BETWEEN THE THUS ADHESIVE-COATED STRIPS; EXPANDING SAID COLLAPSIBLE SHAPING MEMBERS WHILE ARRANGED BETWEEN THE STRIPS; COMPRESSING THE ADHESIVE-COATED STRIPS TOGETHER WITH THE THUS EXPANDED SHAPING MEMBERS ARRANGED BETWEEN SAID STRIPS SO AS TO JOIN TOGETHER THE STRIPS THUS SHAPED BY THE SHAPING MEMBERS AT POINT SPACED BY THE SHAPING MEMBERS; THEREBY FORMING THE STRIPS INTO A CELLULAR STRUCTURE; AND WITHDRAWING THE SHAPING MEMBERS FROM BETWEEN THE THUS SHAPED JOINED STRIPS. 